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Sunday, October 10, 2010

An Introduction to Sake (Part One)

Although sake has been brewed for centuries, it has been known in the western world for little over a hundred years. Sake distribution has greatly improved with the export and popularity of sushi culture, but only recently has high quality sake become available in the United States. The rich variety of styles and increased availability add to the appeal of this truly unique beverage, and extend its appraisal far beyond the sushi counter.

Drink of the Gods, a source of purity

In Japan, drinking sake has long been considered a way to get closer to the deities, in both ancient and modern culture. As a symbol, it is intimately connected with social and religious ceremony. The essential elements of sake brewing are rice and water, both powerful symbols in Japan. Rice has long been the staple food of Japan, a symbol of fertility and even a form of currency, while water is a universal symbol of purity.

The water used in crafting sake is perhaps the most defining element of its character, since water makes up at least eighty percent of its final volume. The ideal spring water contains traces of phosphates, potassium and magnesium, which assist in the brewing of sake. Water with these elements is sometimes called goshinsui, "holy water." The presence of iron and manganese hinder the process. The Kansai area has long been regarded as a brewing center because it has ideal water. Whether the water is hard or soft also determines how the sake will be crafted. Kobe is well known for its kosui (hard water), which favors full flavored brewing, while nearby Kyoto has nansui (soft water), allowing for a light and fragrant crafting.

Rice for One Purpose, polishing diamonds of starch

The best rice for brewing sake has a high starch content at its core. In fact, it is too starchy for human consumption. There are over one hundred varieties of rice in use today, some with formidable names like gohyakumangoku, tamazakae, miyama nishiki, and the most widely used yamada nishiki. The climate in Japan varies from region to region, and different varieties grow in these different climates. However, unlike wine, sake is not categorized by rice varietal, but by the amount of polishing the rice undergoes. By milling away the outer layers, which contain the bran, fats and proteins, the brewer reaches a more abundant layer of pure starch.

This high starch interior is called shinpaku, the "white heart." The impurities in the outer layers produce undesirable flavors. The more the rice is milled, the more expensive the sake will be. This is not unlike the higher prices commanded by low yield, high quality fruit on the vines of premium vineyards. The effect of milling the rice has a similar effect on the yield of production. It takes a lot of rice to make sake, since the water to grain ratio for brewing sake is 1.3 to 1 (in contrast to brewing beer, which has a water to grain ratio of 9:1). Obviously, if you are milling away half of this special rice, you will only have half of the final yield.

Koji, the Magical Mold

The polished rice is then washed and soaked in very exacting times, often with a stopwatch in hand. The size of the milled rice grain will affect the soaking time, so that the steaming of the rice can be as consistent as possible. This process is called gentei kyusui, "limited water absorption." The steaming is also carefully monitored, since overcooked rice will ferment too quickly for flavor development, and undercooked rice will only ferment on the outside.

A small portion of the steamed rice is inoculated with a special mold called koji. It takes about two days to complete the inoculation, which then resembles puffed rice with an aroma of roasted chestnuts. This miraculous mold is not a dark mildew, but rather a fragrant white mold that will later break down the starch molecules of the rice, and convert them into glucose, a process known as saccharification. Koji also provides its own unique flavor and aroma to the sake.

Once the koji is made, sake brewing can begin by making a yeast starter called shubo, colloquially known as moto. Shubo means "sake mother." It is formed by combining koji, water, steamed rice and yeast. In the modern sokujo method, lactic acid is added to hasten the development of the shubo. It creates a sour, high acid environment that inhibits the development of unwanted bacteria and wild yeasts. The koji begins to make the mash thick and sweet. the shubo is ready in about two weeks. The old-fashioned yamahai and kimoto methods allow the natural development of lactic acid, which acquires flavor from ambient yeasts and bacteria, and takes twice as long to develop shubo.

The Craft of Brewing

The shubo is now used to create the main mash called moromi. This is one of the most fascinating and unique processes of sake brewing. In order to maintain the temperature and acidic environment for the yeast culture, the volume of the mash must be gradually increased over a four day period. This process is called sandan shikomi, "three stage brewing." The moromi is doubled in size on the first day, then allowed to rest for one day. This is called the oroshi, the "dancing" of yeast cultures as they recover from the culture shock. Then the moromi is doubled on the third day, and again on the fourth day, when it reaches its final volume. With the yeast healthy, fermentation and saccharification happen simultaneously. This process is unique to sake brewing, known as multiple parallel fermentation.

The fermentation happens at low temperatures, a harsh environment for yeast. This stress on the yeast creates the desired fragrances and flavor of sake brewing. After about 25 days, the fermentation is completed between 18 and 20 percent alcohol. There are two classifications of sake in the market today. For honjozo sake, an addition of brewer's alcohol is added in order to extract some of the volatile fragrances that would otherwise remain with the solids that are to be pressed from the sake. No additions are allowed for junmai sake, which means "pure rice."

The sake is pressed to remove the kasu, or sake lees. Sake lees are used for pickles and soups in Japanese cuisine, just as the grape lees were once used for traditional coq au vin in French cuisine. This pressing of sake is achieved by means of a drip method for the highest grade sake, and usually by air pressing machinery (Yabuta press) for the vast majority. At this point, the sake is ready to drink.

Bottling and Sake Styles

There is an expression in Japanese, "sake zukuri ban ryu." They say that sake is the school of 10,000 ways, and this is certainly true throughout the process of making it. In the second part of this article, I will describe the various ways sake may be finished before and during bottling, which highlight different parts of its character. Terms like genshu, namazake, hiyaoroshi and nigori all describe how it is finished in these final stages. A beverage with 10,000 ways has a sake style for everyone.